U.S. Geological Survey Geochemical Reference Materials and Certificates
U.S. Geological Survey
Certificate of Analysis
Material used in the preparation of this reference material was collected from a quarry located in Twin Sisters Range, approximately 20-due-miles east of Bellingham, Washington. The Twin Sisters dunite is composed of virtually unaltered, coarse grained enstatite bearing dunite with accessory amounts of chromite and chromium diopside (Ragan, D.M., 1963). Mineralogical analysis of DTS-2B reveals that the dominant mineral is Fosterite (90+%) with minor amounts of chromite and trace amounts of lizardite. DTS-2B was collected from the same general location as DTS-1.
Element concentrations were determined in a round robin study involving 20 international laboratories. Recommended values are listed when analytical results provided by three independent laboratories using a minimum of two independent analytical procedures are in statistical agreement. Information values with standard deviations are listed when at least two independent laboratories have provided information. Information values without standard deviations represent information from a single laboratory or analytical procedure.
Recommended Values | Certificate Information | Bibliography | Glossary | Notes | Order and Pricing Information
| Element | Wt % | ± | Oxide | Wt % | ± | |
|---|---|---|---|---|---|---|
| Al | 0.24 | 0.03 | Al2O3 | 0.45 | 0.06 | |
| Ca | 0.09 | 0.01 | CaO | 0.12 | 0.01 | |
| Fetot | 5.43 | 0.15 | Fe2O3tot | 7.76 | 0.21 | |
| Mg | 29.8 | 1.1 | MgO | 49.4 | 1.8 | |
| Si | 18.4 | 0.4 | SiO2 | 39.4 | 0.8 |
| Element | µg/g | ± | Element | µg/g | ± | |
|---|---|---|---|---|---|---|
| Co | 120 | 10 | Ni | 3780 | 220 | |
| Cr | 15500 | 1100 | V | 22 | 8 | |
| Mn | 830 | 40 | Zn | 45 | 5 |
| Element | Wt % | ± | Element | µg/g | |
|---|---|---|---|---|---|
| Fe(II) | 4.27 | 0.20 | Ba | 16 | |
| Na | 0.02 | Cu | 3 | ||
| Ge | 0.7 | ||||
| Pb | 4 | ||||
| Rb | 2 | ||||
| Sb | 0.6 | ||||
| Sc | 3 | ||||
Denver, Colorado
March 2001
Dr. Stephen Wilson
U.S. Geological Survey
Crustal Imaging and Characterization Team
Ragan, D.M., 1963, Emplacement of the Twin Sisters Dunite, Washington, American Journal of Science, 261:549-565
| Symbol | Definition |
|---|---|
| ± | One standard deviation |
| Wt % | Weight percent of element/oxide as received |
| µg/g | Micrograms of element per gram of sample, as received |
Unless otherwise indicated, total element concentrations are reported for material on an as-received basis.
USGS reference materials (RMs) may be obtained directly from Dr. Stephen A. Wilson. The price for each bottle of RM is $80.00 (U.S. dollars) except DGPM-1, which is $175.00 (U.S. dollars). For domestic orders, this cost includes all shipping and handling charges using normal mail delivery. For foreign orders, delivery charges will be added to the final bill. Urgent requests for RMs should be initiated by Fax or e-mail. If required, overnight delivery is available with these charges added to the final bill.
Dr. Stephen A. Wilson
U.S. Geological Survey
Box 25046, MS 964
Denver, CO 80225
Tel: 303-236-2454
FAX: 303-236-3200 or 303-236-1425
e-mail: (wilson)
Domestic customers: Payment options include purchase order, check, money order, or credit card (Visa, Mastercard).
International customers: Payment on foreign orders can only be made using the following:
Payments for domestic or international orders using a credit card receive a 10% discount on the per bottle price.
Beginning in 2006, users of USGS geochemical reference standards must complete a user agreement form prior to the order being purchased.
User agreement for domestic users: Word format, 56 KB and PDF format, 24 KB.
User agreement for foreign users: Word format, 56 KB and PDF format, 28 KB.
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